{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Challenge Notebook"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Problem: Move all zeroes in a list to the end.\n",
    "\n",
    "* [Constraints](#Constraints)\n",
    "* [Test Cases](#Test-Cases)\n",
    "* [Algorithm](#Algorithm)\n",
    "* [Code](#Code)\n",
    "* [Unit Test](#Unit-Test)\n",
    "* [Solution Notebook](#Solution-Notebook)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Constraints\n",
    "\n",
    "* Is the input an array of ints?\n",
    "    * Yes\n",
    "* Is the output a new array of ints?\n",
    "    * No, do this in-place\n",
    "* Do we need to maintain ordering of non-zero values?\n",
    "    * Yes\n",
    "* Can we assume the inputs are valid?\n",
    "    * No\n",
    "* Can we assume this fits memory?\n",
    "    * Yes"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Test Cases\n",
    "\n",
    "<pre>\n",
    "* None -> TypeError\n",
    "* [0, 1, 0, 3, 12]\n",
    "* [1, 0] -> [1, 0]\n",
    "* [0, 1] -> [1, 0]\n",
    "* [0] -> [0]\n",
    "* [1] -> [1]\n",
    "* [1, 1] -> [1, 1]\n",
    "</pre>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Algorithm\n",
    "\n",
    "Refer to the [Solution Notebook]().  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Code"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Solution(object):\n",
    "\n",
    "    def move_zeroes(self, nums):\n",
    "        # TODO: Implement me\n",
    "        pass"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Unit Test"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**The following unit test is expected to fail until you solve the challenge.**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# %load test_move_zeroes.py\n",
    "import unittest\n",
    "\n",
    "\n",
    "class TestMoveZeroes(unittest.TestCase):\n",
    "\n",
    "    def test_move_zeroes(self):\n",
    "        solution = Solution()\n",
    "        self.assertRaises(TypeError, solution.move_zeroes, None)\n",
    "        array = [0, 1, 0, 3, 12]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [1, 3, 12, 0, 0])\n",
    "        array = [1, 0]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [1, 0])\n",
    "        array = [0, 1]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [1, 0])\n",
    "        array = [0]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [0])\n",
    "        array = [1]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [1])\n",
    "        array = [1, 1]\n",
    "        solution.move_zeroes(array)\n",
    "        self.assertEqual(array, [1, 1])\n",
    "        print('Success: test_move_zeroes')\n",
    "\n",
    "\n",
    "def main():\n",
    "    test = TestMoveZeroes()\n",
    "    test.test_move_zeroes()\n",
    "\n",
    "\n",
    "if __name__ == '__main__':\n",
    "    main()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Solution Notebook\n",
    "\n",
    "Review the [Solution Notebook]() for a discussion on algorithms and code solutions."
   ]
  }
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